This invention relates to the evaluation of wires for insulation degradation, sometimes referred to as xe2x80x9cagingxe2x80x9d.
Many complex systems involve substantial amounts of wiring and wiring harnesses. Examples of such systems include aircraft, ships, power plants, factories, vehicles, spacecraft, and missiles. Although the aging of wire was not recognized until recently, it has now been established that aging is one reason for the failure of wire.
To be more specific, the insulation surrounding the conductor may age, resulting in cracks, some of which cannot be detected by a visual inspection. Such cracks can permit such phenomena as arcing, with potentially disastrous results in systems such as aircraft in-flight.
Complex systems such as those mentioned above therefore require an evaluation of the wire to be performed even when the wire appears to be sound. Unfortunately, the wiring in such systems tends to be very long, run through bulkheads and other features which make its removal difficult or impossible, or be strapped down with connectors, retainers, and sleeves. In other words, the wire is in an xe2x80x9cinstallationxe2x80x9d. When wire is in such an installation, it is typically impractical to effect the complete removal and evaluation of all the wire.
One approach to evaluating such systems"" wiring is to evaluate some of the wiring in-situ. Such an evaluation may be performed, for example, according to the method described in U.S. Pat. No. 6,225,811, which issued on May 1, 2001 to Dr. Armin M. Bruning et al, and which is assigned in common with the present application to LECTROMECHANICAL DESIGN COMPANY of Sterling, Va.
For an evaluation of wiring at the installation according to any approach, however, highly skilled personnel are required for performing such an evaluation. Planning meetings are required. Much coordination may be necessary between the entity owning the system (often a government agency) and the entity performing the evaluation (often a contractor). Such meetings, preparation, coordination, and execution can be expensive and time-consuming. Moreover, given the great shortage of such highly skilled personnel in the industry, there is a practical limit to the number of systems that can be evaluated in the light of the fact that the personnel must travel to the system.
The same drawbacks exist in situations in which parts of the wire are removed from the installation and later tested by these highly skilled personnel. The personnel have to travel to the site, choose wire specimens for removal, oversee the removal, prepare the wire specimens for transport, and then test and provide results to the entity owning the system.
What is needed is a new approach to the evaluation of wiring in complex systems that avoids the deficiencies of present approaches.
According to one aspect of the invention, there is provided a kit-based approach to the evaluation of wiring. In this approach, the evaluation personnel do not need to travel to the system. Instead, a kit is sent from the evaluation personnel to the entity controlling the system (xe2x80x9ccustomerxe2x80x9d for the remainder of the discussion). The kit includes the necessary instructions and equipment for the customer to effect a safe and trouble-free removal of appropriate wire specimens from the system, the necessary instructions and equipment for the customer to preserve pre-removal environmental information, the necessary instructions to make intelligent selections for the selection of wire specimens, and the appropriate protective packing environment to ensure the specimens are not damaged during shipment.
Because the customers select the wires for removal, remove the wires, and send them to the evaluation personnel, it is no longer necessary for the evaluation personnel to travel to the system to perform the evaluation. This overcomes the above identified problems with the known approaches.
The manner in which the foregoing object is achieved, as well as other objects, will become clear from reading the description below which teaches the invention by way of various specific exemplary embodiments explained in detail, and further by way of various specific illustrations in the enclosed drawing figures.